title: Silicon and germanium nanoparticles with tailored surface chemistry as novel inorganic fiber brightening agents.
abstract: Low-molecular-weight organic molecules, such as coumarins and stilbenes, are used commercially as fluorescent whitening agents (FWAs) to mask photoyellowing and to brighten colors in fabrics. FWAs achieve this by radiating extra blue light, thus changing the hue and also adding to the brightness. However, organic FWAs can rapidly photodegrade in the presence of ultraviolet (UV) radiation, exacerbating the yellowing process through a reaction involving singlet oxygen species. Inorganic nanoparticles, on the other hand, can provide a similar brightening effect with the added advantage of photostability. We report a targeted approach in designing new inorganic silicon- and germanium-based nanoparticles, functionalized with hydrophilic (amine) surface terminations as novel inorganic FWAs. When applied on wool, by incorporation in a sol-gel Si matrix, the inorganic FWAs improved brightness properties, demonstrated enhanced photostability toward UV radiation, especially the germanium nanoparticles, and also generated considerably lower levels of reactive oxygen species compared to a commercial stilbene-based organic FWA, Uvitex NFW.
authors.affiliation: Protein Quality and Function, AgResearch Lincoln Research Centre, Christchurch 8140, New Zealand. santanu.deb-choudhury@agresearch.co.nz
authors.forename: Santanu
authors.initials: S
authors.lastname: Deb-Choudhury
authors.forename: Sujay
authors.initials: S
authors.lastname: Prabakar
authors.forename: Gail
authors.initials: G
authors.lastname: Krsinic
authors.forename: Jolon M
authors.initials: JM
authors.lastname: Dyer
authors.forename: Richard D
authors.initials: RD
authors.lastname: Tilley
mesh_terms: D000818:Animals; D004396:Coloring Agents / Q000737:chemistry*; D005857:Germanium / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D014935:Wool / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D005857:Germanium; D012825:Silicon